You guys are taking the Urban Dictionary thing too seriously lol.
Everyone has their own opinion on what "girl next door" means. We can agree that one of the factors is how they look, but I think what is more important is their personality which should have characteristics of being sweet-natured, innocent, and pure.
And so I find it difficult to see how an aggressive, slut like Ai Uehara fits this description. Compare the shy, sweet personality of Airi Suzumura to the aggressive, cock hungry style of Ai Uehara and I think you'll know what I mean.
Based on her look, I agree with ding73ding, Ai Uehara fits the category. While I would like to be 100% agree with you needs more loli, about the personnality, even if they are not the majority, some girls can be aggressive like Ai. I don't personally know any girl in that case, but when I see on TV spring break parties ... I wouldn't be surprised that some girls go really wild. For example, maybe your neighbour like to do 3-4P on saturday nights and you can't notice that when you see her because she hides it. Another example, the former owners of my house are like that (they are over 50 I think). My neighbour said once that he saw the woman naked and she greeted him naked (there is a gate so you can't see in the garden if it's not open) and talked to him without any problem. Otherwize, she was normal when she was outside her home, in the street, ... so if he didn't enter, he would have never known.
When you see Ai Uehara, you couldn't imagine how dirty she is. But when you see Hitomi or Anri Okita, you can guess that they are pornstars. For me, that's really what describes the "next door" type (innocent and pure would be more the "Kawaii" girl).